This invention relates to the need for morphologically stable metal catalysts where the morphology on the nanometer scale does not rapidly degrade during use of the catalyst. One example where catalyst degradation during operation is a serious problem is in the area of fuel cells. Fuel cells are an efficient and environmentally benign source of energy that shows promise for applications requiring fast start and flexible operational properties, as in light-duty vehicles. However, successful commercialization of fuel cells in this application has been impeded by the lack of durability and high cost of some fuel cell materials. A major factor in determining the lifetime of a fuel cell stack is the loss of active surface area of the platinum-based catalysts. Loss of active surface area can result from oxidation, dissolution, particle migration, sintering, coursening, and Ostwald ripening. Previous attempts to solve this problem have focused on alloying platinum with non-precious metals, such as cobalt or nickel, and on supporting platinum on various electrically conductive materials, such as carbon black or carbon nanotubes.
This present invention embodies a different approach to obtaining durable catalysts for which the surface area does not rapidly degrade due to such processes as sintering and Ostwald ripening.